This invention generally relates to convertible roofs for automotive vehicles and, more particularly, to a convertible roof system that uses rotary actuators to control the movement of the retraction mechanism.
Traditional soft-top convertible roofs for automotive vehicles typically employ three, four or five roof bows, having an inverted U-shape spanning transversely across the vehicle for supporting a vinyl, canvass or polyester fabric pliable roof cover. A number one roof bow is mounted to a pair of front roof rails and is typically latched to a stationary front header panel of the automotive vehicle body disposed above the front windshield. A number two roof bow is typically mounted to either the front roof rails or to the center roof rails which are pivotally coupled to the front roof rails. The number three roof bow is typically mounted to either the center roof rails or to the rear roof rails which are pivotally coupled to the center roof rails. Any remaining roof bows are commonly mounted to the rear roof rails. The roof cover can also have a hard or rigid portion along with the pliable portion. For example, reference should be made to U.S. Pat. No. 5,429,409 entitled “Convertible Top,” which is incorporated by reference herein.
The movement of the roof rails and the roof bows is typically controlled by linkage assemblies, such as two pairs of four-bar linkage assemblies on each side of the vehicle. When moving the convertible roof between the raised and stowed positions, the motion of the roof rails and roof bows and roof cover are carefully coordinated to avoid interfering with one another. To obtain the desired motions and the timing for the motions, the linkage assemblies may include complex linkage shapes or arrangements. These complex arrangements can add to the cost of producing the convertible roof. Additionally, these complex linkages may increase the packaging space required to stow the convertible roof in the retracted position. The increased packaging space diminishes the space in the vehicle available for other purposes such as storing goods and/or the size of the passenger compartment. Thus, it would be advantageous to provide a convertible roof that uses a minimal packaging space. Furthermore, it would be advantageous if such convertible roof were economical to produce.
In addition to the packaging space, these complex linkages may require a significant amount of torque to be generated at the interface of the convertible roof with the vehicle body to retract and extend the convertible roof. The large torque is typically required due to the second four-bar linkage that is used to drive the front portion of the convertible roof. This second four-bar linkage is typically driven from the first four-bar linkage that is associated with the vehicle body. The requirement for a large torque at the interface of the convertible roof to the vehicle body increases the cost of the actuators used to operate the convertible roof. Thus, it would be advantageous to produce a convertible roof having a lower torque requirement at the interface between the convertible roof and the vehicle body.
The linkage assemblies used to control and coordinate the motion of the various components of the convertible roof are typically formed by casting or stamping. When these linkages are cast or stamped, the holes therein that are used to provide pivotal connections between the linkages and other components of the convertible roof. The holes, however, have limited tolerances. As a result of the limited tolerances, the linkages may have some play or slop in them that is undesirable. Thus, it would be advantageous to provide a convertible roof system wherein the control of the various components of the convertible roof is more precise.
In accordance with the present invention, a convertible roof system is provided which includes rotary actuators which are operable to pivot the roof rails relative to one another and a portion of the actuator is disposed within one of the roof rails. In another aspect of the present invention, a convertible roof for an automotive vehicle is provided which includes a retractable roof cover with a flexible portion and at least three rotary actuators that are each located at a pivot joint between the roof rails and are operable to rotate the roof rails relative to one another or to the vehicle. In still another aspect of the present invention, a roof rail for a convertible roof is provided that has a fluid chamber within the roof rail and a fluid driven piston that is disposed within the fluid chamber. The present invention also provides for a method of manufacturing a convertible roof with an integral rotary actuator.
The use of the rotary actuators reduces the need for complex linkage assemblies to control and coordinate the motion of the various roof rails and components of the convertible roof. Additionally, by locating at least a portion of the rotary actuators within the roof rails, the actuators take up less space and reduce the packaging space required for stowing the convertible roof. Additional objects, advantages and features of the present invention will become apparent from the following description and the pending claims, taken in conjunction with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.